Saved By an Alien Warlord by Calista Skye

Earth has been ravaged. We’re the survivors.
Information is not just power, it can be the difference between life and death. And I’ve braved every kind of danger to get this vital information that will save the remaining members of my species. All I have to do is make it to Denver alive. But with few supplies left after crossing scorching deserts and freezing mountains on foot, I’m captured.
Our conquerors do not respect me as a scientist. They do not see me as a threat. To them, I am a human female worthy only of being an alien bride.
That’s alright. I will use their arrogance against them.
Because while human bodies are weak, our will is strong.
And there is nothing I won’t do to save my people.